In downtown Kamloops, the concentration of fine particulate matter in the air from 2 to 3 p.m. averaged 684.5 micrograms per cubic metre, whereas most areas in Metro Vancouver have hovered between 50 and 60 in recent days.

For comparison sake, China considers a daily average above 300 to be hazardous.

Kamloops airport cancellations

The air pollution is being caused by the wildfires that have been raging to the west and north of Kamloops for several weeks, particularly the Elephant Hill wildfire, now measured at over 80,000 hectares.

Uncharted territory

CBC meteorologist Johanna Wagstaffe says it's uncharted territory for a city like Kamloops to have their Air Quality Health Index above 10 for so long.

"We just don't have any studies looking at what a factor over 10 means in terms of health impacts," she said, adding that there's been no studies on the specific effects from forests fires, as opposed to straight up pollution.

"We don't know how much worse a 49 is than a 10. All we can say is anything over seven is bad."

And while the index may not stay as high as 49 going forward, the general prognosis is unlikely to improve in the next 24 hours.

"A shift in winds this weekend might help improve the air quality situation across the whole province, but there's so much smoke, it'll be hard to say whether it's enough to flush things out in Kamloops."